Textbook Solutions: Life in the Desert | Window on the Word Class 7: Solutions, Notes & Worksheets PDF Download

A. Choose the correct answer.

1.
Ans: (c)

2.
Ans: (a)

3.
Ans: (c)

4.
Ans: (d)

5.
Ans: (a)

B. Fill in the blanks. 

1.
Ans: The Sahara desert has the Atlantic Ocean to the west.

2.
Ans: The hot sandy winds that blow across Egypt in late-winter and spring is called Khamsin.

3.
Ans: The men of the Tuareg nomadic community of the Sahara can be identified by the blue robes they wear.

4.
Ans: Ladakh lies on the leeward side of the Himalayas.

5.
Ans: Two of the important glaciers found in Ladakh are the Siachen and the Nubra.

6.
Ans: Fruits like apple, apricot and walnuts are grown in Ladakh during summer.

7.
Ans: A wool called Pashmina is derived from the chiru.

C. Mark the following as True or False. Correct the ones that are false.

1.
Ans:  False
The Sahara desert consists largely of rock-covered plateaus and plains made of sand and gravel.

2.
Ans: False
Cold deserts are found mostly in the interiors of continents in the temperate regions and high-altitude regions like Ladakh.

3.
Ans: False
The area of the Sahara is more than two and a half times the size of India.

4.
Ans: True

5.
The Changthangi, or pashmina goat, is raised mainly for its wool.

D. Answer in one or two sentence

1.
Ans: The Bedouin and Tuareg are two nomadic tribes of the Sahara desert. Their main occupation is rearing animals like goats, camels, sheep, donkeys and cattle for transport, milk, hide, and wool.

2.
Ans: The main physical features of the Sahara are hamadas (elevated, rock-covered plateaus), regs (plains made of sand and gravel) and ergs (vast plains of desert covered with sand).

3.
Ans: An oasis is a fertile spot in a desert where water is found. It is useful as it provides a steady supply of water, enabling agriculture and the growth of trees, providing a habitat for humans and animals.

4.
Ans: The discovery of petroleum, iron, manganese, and uranium changed the lives of people of the Sahara. The rich deposits led to the development of industries in the region, encouraging nomadic communities to settle down and modernise their transportation.

5.
Ans: Ladakh is a high-altitude cold desert. It is located in the northern tip of India.

E. Answer in a paragraph.

1.
Ans: Hot deserts, located in tropical regions along the western coasts of continents, experience extremely high temperatures throughout the year, with minimal seasonal variation. Examples include the Sahara and the Arabian Desert. Cold deserts, on the other hand, are found in temperate regions, mostly in the interiors of continents. They experience extremes of temperature and receive practically no rain, with short summers and extremely cold winters. Examples include the Siberian desert and the Ladakh region of the Himalayas.

2.
Ans: In the Sahara desert, regs are plains made of sand and gravel also known as desert pavements, hamadas are elevated rock-covered plateaus from which the sand has been blown away, and ergs are vast plains of desert covered with sand featuring huge sand dunes. Regs and hamadas make up 70% of the Sahara, while ergs make up just 20%.

3.
Ans: The Sahara experiences an arid and extreme climate. Summers are very hot and winters range from cool in the coastal areas to very cold in the interiors. The northern plateaus sometimes experience snowfall. The daily range of temperature is also extreme, with an average difference of 15°C to 20°C between the temperature during the day and the temperature at night.

4.
Ans: In Ladakh, several salt-water lakes like Pangong Tso and Tso Kar, and rivers like Indus and Nubra, are found. Despite the presence of these water bodies, Ladakh is a desert region because it lies on the leeward side of the Himalayas and is hence deprived of the monsoon winds that bring rainfall to most parts of India.

5.
Ans: Due to aridity, lack of fertile soil, and long winters, most of Ladakh consists of bare, windswept expanses of land. Patches of trees, grasses and shrubs grow in the river valleys and near springs. Animals found in this region include the snow leopard, the red fox, the Asiatic ibex and the chiru. Birds like the Tibetan snow cock, the brown-headed gull, the black-necked crane, ravens and robins are also found here.

6.
Ans: The people of Ladakh engage in agriculture, horticulture, sericulture, cattle rearing, handicrafts and tourism. They rear sheep, yaks and goats for milk, meat, and hide. They cultivate crops like wheat, barley, potato, peas, beans and turnip, and fruits like apple, apricot and walnuts.

7.
Ans: The people of Ladakh have adapted to their harsh environment in various ways. They use dry toilets and turn the excreta into rich organic manure to deal with water scarcity. They grow crops like barley that use little water. Their food and clothing are adapted to the environment, with abundant use of butter for warmth and clothing made of wool, fur or animal skin.